Undecided (adjective)

1. Not having made a decision; not having chosen.
2. Not having a clear opinion or preference.

Origin:

From un- ("not") + decided, from old english deciden ("to decid.e")

Examples:

1. The voter was still undecided on who to vote for.
2. She was undecided about which dress to wear.
3. He was undecided on whether to accept the job offer or not.
4. The issue remained undecided.
5. The students were undecided on the subject of the debate.